After decades of poor progress in vertical takeoff and landing
craft relative to that of other kinds of aircraft we see this
DARPA Solicitation.
It does not surprise me that the advances made in altitude and speed did not carry with it all of the capabilities of flight that we value. In my view, we have simply
been advancing along the wrong path.

Our initial imitation of birds was perhaps inevitable, but
nonetheless unfortunate. Evolutionary constraints guarantee that we will not see a suitable bird to imitate any time soon.

I suggest a different starting point - a craft that is circular
as seen from above or below, and approximately elliptical as seen from the direction of the horizon - a saucer. This basic configuration offers many options for
propulsion, optimum sonic stealth and maximum vertical to horizontal air resistance.

Some propulsion options require the outer shell to spin
about the center. In this event, the crew must be standing or sitting on a non-spinning platform and viewing outside scenes through either a transparent band of
the outer shell or a video representation. A non-spinning platform can be arranged if some of the mass of the craft is spinning in the direction opposite to
that of the outer shell and has an inertial stabilizer such as a gyroscope. This mandates at least three frames of reference, two magnetically suspended from a
vertical shaft at the center.

If aerodynamic propulsion and a spinning outer shell is
chosen, either articulating peripheral blades (small compared to the diameter) or a multiplicity of peripheral jet-exhaust ports are indicated.
Electromagnetic propulsion can be used with or without a spinning outer
shell.

For a craft intended exclusively for the atmosphere and
using aerodynamic propulsion, a split outer shell is possible. The top half and the bottom half would spin in opposite directions and use either articulating
peripheral blades or a multiplicity of peripheral jet-exhaust ports to avoid the necessity of inertial stabilization.

Contact

Please feel free to write to me directly for more information
or to make suggestions or comments. My email address is jim@futurebeacon.com. You can also go to
my contact page to get my full contact information. Suggestions, questions,
additional information and critiques are very welcome.